Chapter 1: Hello, World! Solved

Description

https://www.youtube.com/playlist?list=PLhOuww6rJJNP7UvTeF6_tQ1xcubAs9hvO

Write a program to enthusiastically greet the world:

$ ./hello.py
Hello, World!

The program should also accept a name given as an optional --name parameter:

$ ./hello.py --name Universe
Hello, Universe!

The program should produce documentation for -h or --help:

$ ./hello.py -h
usage: hello.py [-h] [-n str]

Say hello

optional arguments:
  -h, --help          show this help message and exit
  -n str, --name str  The name to greet (default: World)

Run pytest -xv test.py (or make test) to ensure you pass all the tests:

$ make test
pytest -xv test.py
============================= test session starts ==============================
...
collected 4 items

test.py::test_exists PASSED                                              [ 25%]
test.py::test_usage PASSED                                               [ 50%]
test.py::test_default PASSED                                             [ 75%]
test.py::test_input PASSED                                               [100%]

============================== 4 passed in 0.41s ===============================